GSLIB Help Page: QPPLT

Description:

qpplt takes univariate data from two data files and generates
either a QQ or a PP plot. QQ plots compare the quantiles of two
data distributions, and PP plots compare the cumulative probabilities
of two data distributions. These graphical displays are used to
compare two different data distributions, e.g., compare an original
data distribution to a distribution of simulated points.

Parameters:

datafl1: The data file for the first variable (x axis)
in a simplified GeoEAS format.

ivr1 and iwt1: column number for the variable and the
weight. If iwt1 less than or equal to 0, equal weighting is
considered.

datafl2: The data file for the second variable (y axis)
in a simplified GeoEAS format. Note: It is possible that
datafl2 is the same as datafl1

ivr2 and iwt2: column number for the variable and the
weight. If iwt2 less than or equal to 0,
equal weighting is considered.

tmin and tmax: all values strictly less than tmin
and strictly greater than tmax are ignored.

outfl: file for PostScript output.

qqorpp: The flag to tell the program whether to construct a QQ
plot (qqorpp=0) or a PP plot (qqorpp=1).

npoints: number of points to use on the QQ or PP plot (should
not exceed the smallest number of data in datafl1 /
datafl2

xmin and xmax: minimum and maximum limits for x
axis.

ymin and ymax: minimum and maximum limits for y
axis.

ilog: =0 then an arithmetic scaling of the axes
is used, =1 then a logarithmic scaling (base 10) is used.
Note that the log scaling only applies to the QQ plot; the axis for
the PP plot are between 0 and 1

title: a 40character title for the top of the plot.
A short description of the program